Folded Separator Electrode Assembly for Higher Pouch Cell Density
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Solution Overview
Problem
The existing electrode assemblies in secondary batteries suffer from a reduction in energy density due to the formation of spaces between the side portion of the separator and the electrode, which is caused by the separator surrounding the outermost portion of the stack, leading to wrinkles and inefficient use of space.
Innovation Solution
The electrode assembly is designed with a first separator that includes folded parts on alternating sides of the stack, with side sections bonded to a second separator, and the assembly is compressed to condense the stack, reducing the space between the outermost separator and the stack.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a wound rotor type induction motor is used to provide high starting torque, then the starting torque is improved, but the structure becomes more complex and costly due to additional components
Solution Approach 1:
The patent extracts the function of providing high starting torque from the motor structure itself by adding an external starting torque assisting device. This separates the high starting torque function from the motor's internal complexity, allowing the motor to remain simple while achieving the desired torque through external assistance.
Solution Approach 2:
The patent introduces an intermediary starting torque assisting device that includes a starting torque sensor and a starting torque motor. This intermediary device mediates between the power source and the compressor, providing the necessary starting torque without requiring the compressor motor itself to be complex.
2Device complexity
If a three-phase induction motor is used, then the motor structure is simple and cost-effective, but high starting torque cannot be obtained
Solution Approach 1:
The patent merges a simple three-phase induction motor with an external starting torque assisting device. The three-phase motor provides the basic simple and cost-effective structure, while the assisting device is combined with it to supplement the starting torque, achieving both simplicity and high starting torque capability.
Solution Approach 2:
The starting torque assisting device performs preliminary action by providing the necessary starting torque before the three-phase motor can effectively start the compressor. The sensor detects the starting condition and activates the assisting device in advance to ensure sufficient starting torque is available.
3Reliability
If the inverter stops outputting frequency modulation voltage during abnormal conditions, then safety is improved, but the compressor cannot be restarted without manual intervention
Solution Approach 1:
The patent implements self-service by enabling the system to automatically restart after an abnormal condition. When the inverter stops outputting frequency modulation voltage due to an abnormality, the control unit automatically detects the condition, controls the contactor to connect the starting torque motor, and initiates restart without requiring manual intervention, thus maintaining both safety and ease of operation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design increases the electrode density and energy density by condensing the space between the outermost separator and the stack, allowing the assembly to fit within the dimensions of a pouch or can without altering the size, thereby improving the efficiency and flexibility of battery design.
Implementation Method 1
a starting torque sensor that detects a starting torque of the compressor
Implementation Method 2
a starting torque motor that operates in response to the output of the starting torque sensor and that has a rotational axis intersecting the rotational axis of the compressor
Data Source
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AI summary
An electrode assembly includes a stack and a second separator. The stack includes first and second electrodes and a first separator folded in a zigzag configuration and including spacer sections and respective side sections between the spacer sections. The first and the second electrodes are alternately disposed between first separator spacer sections The second separator extends along an upper surface, a lower surface, and at least one pair of opposing side surfaces of the stack. The side sections of the first separator define portions of the side surfaces of the stack on which the first electrode and the second electrode are not disposed. The second separator is bonded to at least one of the side sections.